1. Field of the Invention
The invention concerns a corrugated gear, and particularly a corrugated gear wherein the tooth profile of the flexible gear and the tooth profile of the rigid gear are chosen in such a way that every tooth of the flexible gear can make a loop-shaped movement within a tooth gap of the tooth profile of the rigid internally geared gear, wherein that the movement contour of a tooth of the flexible gear while making its loop-shaped movement determines at least approximately the contour of a tooth gap of the tooth profile of the rigid gear.
2. Description of the Related Art
All corrugated gears include a deformable internal gear. This could be made of metal or could also be made of plastic. A guide curve is used to describe the shape of the deformed internal gear (for example, an ellipse in harmonic drives) (see FIG. 1). If the deformations under load are not considered, or in the case of a too general model, engagement discontinuities or disruptions occur, which have a negative impact on effectiveness and life expectancy (see FIG. 2).
The deformations can occur in a radial direction, for example among the individual rollers or studs or planet arms, or the deformations can occur in the direction tangential to the internal gear, when the internal gear is stretched or stressed in the longitudinal direction during the transmission of torque. When these deformations are not taken into consideration this leads to disruptions in gear tooth engagement, to an increase in tooth flank wear, and, as a result of the deformation of the tooth head in the radial direction, to damage of the gear tooth head and a reduction in gear tooth efficiency. The tooth efficiency has a very large influence on the efficiency particularly in high reduction planetary gears and also in corrugated gears.